Rio never asked AA's help. AA hates Enweil and luvs Rio and entered to war without being asked to do so...
I doubt it has huge impact on things(directly, but ofcourse there could be some side happenings following), AA is small realm, not bordering with Fronen/Enweil...
So, i guess its about to tie up Fronen forces from participating to war, ofcourse if Fronen sees the light and accepts AA's terms, we would be able to hit Devil itself, Enweil!
-Jaune